Abstract Background/Introduction Non-alcoholic fatty liver disease (NAFLD) is a risk for cardiovascular events and malignant tumors as well as liver cirrhosis, and the risk increases with increasing fibrosis of the liver. Thus, the fibrosis-4 (FIB-4) index, developed as a noninvasive test to stage liver fibrosis, may predict the development of hypertension. Purpose The present study investigated the relationship of FIB-4 index with the prevalence and future development of hypertension in the general population. Methods A total of 16125 participants who visited our hospital for a physical check-up at least twice from 2008 to 2018 (male=9700, 52.0±12.3 year-old) were subjected for cross-sectional analysis. Among them, 3995 participants were hypertensive. The remaining 12111 normotensive participants (male=6984, 49.5±11.9 year-old) were followed up for the median of 1643 days with the endpoint being the development of hypertension, defined as systolic blood pressure ≥140mmHg, diastolic blood pressure ≥90mmHg or the use of antihypertensive medication. FIB-4 index was calculated as follows; (age×AST)/(platelet number×√ALT). Results Cross-sectional analysis revealed that FIB-4 index was higher in hypertensive than normotensive participants (1.40±0.74 vs. 1.09±0.54, p<0.001). During the follow-up, 2819 participants (45.7 per 1000 person-year) developed hypertension. The incidence was more frequent in male (55.6 per 1000 person-year) than female participants (32.7 per 1000 person-year, p<0.001). High level of FIB-4 index (≥2.67, n=194) showed a significant impact on the incident hypertension (80.5 per 1000 person-year) as compare with middle (≥1.30, <2.67, n=3082) or low level (<1.30, n=8835) of FIB-4 index (65.4 and 38.8 per 1000 person-year, respectively). Non-adjusted hazard ratio (HR) (95% confidence interval [CI]) of FIB-4 index for the new onset of hypertension was 1.483 (1.416-1.553). In multivariate Cox hazard analysis adjusted for sex, body mass index, systolic blood pressure, pulse rate, serum creatinine, uric acid, HbA1c, LDL-cholesterol, triglyceride, hemoglobin, current smoking, frequent alcohol consumption and family history of hypertension, FIB-4 index was an independent predictor of the development of hypertension (HR 1.321, 95%CI [1.213-1.438]). Similar results were obtained in analyses of male (HR 1.382, 95%CI [1.300-1.470]) and female subgroups (HR 1.369, 95%CI [1.230-1.524]). History of viral hepatitis or frequent alcohol consumption did not affect the results (data not shown). Conclusions FIB-4 index is a useful predictor of the development of hypertension in the general population. Increased risk of cardiovascular events in patients with NAFLD may partially be attributable to the development of or coexistence with hypertension.